They named a function slightly poorly. As if Linus has never done that.

Not only that. They introduced a obscure function, which inner workings are not clear and that is only used by their new code into a global header which is used by many other code parts, which means other people could start using it. This could lead to bugs since the semantics are not clear from the function name or if they change the function in the future. Also they added their pull request much too late to be properly reviewed.